Homebrew broken - "cannot load such file -- vendor/bundle/bundler/setup (LoadError)"

Question

Every time I try to run a brew command, it gives the following error:

/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/2.3.7/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- vendor/bundle/bundler/setup (LoadError)
from /usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/2.3.7/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
from /usr/local/Homebrew/Library/Homebrew/load_path.rb:7:in `<top (required)>'
from /usr/local/Homebrew/Library/Homebrew/global.rb:8:in `require_relative'
from /usr/local/Homebrew/Library/Homebrew/global.rb:8:in `<top (required)>'
from /usr/local/Homebrew/Library/Homebrew/brew.rb:17:in `require_relative'
from /usr/local/Homebrew/Library/Homebrew/brew.rb:17:in `<main>'

I'm not sure if this is an issue with my Ruby/Bundler, since bundler works completely fine in other cases. What might the problem be?

Answer 1

brew update-reset && brew update worked for me.